Aspecimen collection a scientist do research by:
a. assembling a large number of samples for comparison
o
o
b. summarizing the results of another scientist's investigation
o
c providing a way to afford even the most expensive instrument.
o
d. creating a realistic depiction of an imaginary undersea world,

The correct option is A) assembling a large number of samples for comparison.

Explanation:

A specimen can be described as a sample of anything which is used for scientific or biological researches. For example, a sample of blood withdrawn from a person to perform various tests.

Specimens can be collected and stored  and they help scientists by comparing the results of different treatments which they apply to the specimens. Hence, option A is correct.

Other options like Option C are not correct because a specimen has nothing to do with making expensive instruments reliable.