单选题：Questions are based on the following passage．The more choice

Questions are based on the following passage．
The more choices people have, the riskier the decisions they make, according toa new study which sheds light on how we behave when faced with large amounts ofinformation.
Researchers at the University of Warwick and the University of Lugano set up agambling game in which they analysed how decision-making is affected when people arefaced with a large number of potential gambles. They found that a bias in the way peoplegather information leads them to take more risks when they choose a gamble from a largeset of options, a phenomenon which researchers have labelled "search-amplified risk".
Dr. Thomas Hills of the Department of Psychology at the University of Warwick said,"The problem is with the information search strategies people use when faced with a largenumber of options."
For the study,64 participants took part in a game where they had to choose one boxout of a varying number of boxes presented on a computer screen. Each box contained adifferent sum of money--for example ￡1 or ￡ 5--and each box had a certain probabilityof paying out--for example,1 out of 10,1 out of 3, or every time. Participants were ableto "sample" each box by opening it as many times as they liked to determine the payoutamount and to try to deduce the probability of a payout. Once they were satisfied with theinformation they had gathered, they committed to their final choice by choosing a singlebox. The game consisted of five turns, with either an increasing or decreasing number ofboxes per turn.
The researchers found that both the number of boxes per turn and whether thenumber of boxes was increasing or decreasing affected the quality of decision-makingamong the participants. With a higher number of boxes, people made a higher total numberof samples. However, the increase in sampling was not in proportion to the increase in boxnumbers.
These results show that with large choice sets, people gathered a broad range ofinformation on the value of the potential sum they could win, so were aware that therewere boxes with higher payout values. However they were not delving ( 探究 ) deeplyinto that information, which in this context meant they were not fully investigating theprobability of the payout of the higher-value boxes. The researchers also found differencesin decision-making between the "many-to-few group"--those who started with a largenumber of choices which were then decreased--and the "few-to-many group" where the orderwas reversed. The study showed that people who started with smaller choice sets weremore likely than the other group to gather more information across all choice set sizes.
What does "search-amplified risk" mean according to the researchers? A．People do not know how to make choices when faced with a large set of options.
B．People make random decisions when faced with too much choice.
C．People make riskier decisions when faced with a large set of options.
D．People make wise choices when faced with too much choice.