One way to reduce bias in an experiment is to
a. ask only girls a question about a school topic
b. take numerical measurements of the results
c. use descriptive phrases as your data
d. make sure that the results come out the way you want them

The correct option is B.

Bias in science refers to an assumption that an evidence is right or wrong without taking the steps to confirm. It is very important for scientists to reduce the bias that are present in their work in order to obtain valid results. One by which scientific bias can be reduced is by taking numerical measurements of the results.

the correct answer to this question is 2