To remember the four bases found in dna—thymine, guanine, adenine, and cytosine—luke makes up a sentence using the first letter from each base as the first letters for his words, repeating to himself, "the girl ate cookies." which of the following did luke use in this scenario?
(a)-the method of loci
(b)-a mnemonic device
(c)-chunking
(d)-rhyming

(b) - A mnemonic device

Explanation:

A mnemonic device -

It is a technique used by a person to improve or faster the process of a learning .

This can be done by using some codes or tricks to make the concept or words easy and interesting , and can be easy learned .

hence ,

in the question , Luke used the mnemonic to learn the four bases of DNA quickly and efficiently .

"do a testcross with a homozygous recessive plant."