Normally, such questions are called multiple-choice questions, where the choices are enumerated as A, B, C, etc and addressed in manner such as
- choice A, choice B
- answer choice A
The action is not called "coding". It is called enumeration. Therefore each index letter, A, B, C, etc can either be called
- enumerator (enumerator A, enumerator B, etc)
- enumeration index
Choice is different from an enumerator/enumeration index.
Choice/Answer choice is the whole line.
Whereas, enumerator/enumeration index is the letter or number used to enumerate an answer choice.
If you are "documenting", it means your documentation needs to be normally understood. It is unwise and unhelpful to try to invent new words when there already exists established terminology.
There is absolutely nothing inaccurate or imprecise with the use of the term "choice". Professional documentation should be clear, and not confusing.
e·nu·mer·ate (ĭ-no͞o′mə-rāt′, -nyo͞o′-)
tr.v. e·nu·mer·at·ed, e·nu·mer·at·ing, e·nu·mer·ates
- To count off or name one by one; list: A spokesperson enumerated the strikers' demands.
- To determine the number of; count.
[Latin ēnumerāre, ēnumerāt-, to count out : ē-, ex-, ex- + numerus, number; see nem- in Indo-European roots.]
e·nu′mer·a′tive (-mə-rā′tĭv, -mər-ə-) adj.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.