Different birds use different building designs: they can be huge or tiny, made of twigs, grass, leaves, or mud. But most birds follow a similar final
step in the nest-building process. They line the inside of the nest with
something soft, such as a feather.
Once eggs are laid in a nest, the parent birds will spend hour after hour
sitting on them to keep them warm and safe. They need that nice soft
lining for their own comfort.
This is probably the origin of the phrase "feather one's nest.” It means to
do something now that will provide for your own comfort later on.
Make a list of some things you can do now to “feather your nest."

the correct answer is:   [d]:   " diagram "   .

hope this !

    best wishes to you!

a. unlikely

for improbable?

1. the relationship between a pronoun and its antecedent- reference

reference refers to the relationship between mainly pronoun and another unit of grammar- noun phrase or noun.

2. a singular noun naming a collection or group- collective noun.

collective noun refers to the kind of noun which refer to the name of people, thing or anything in collective. for instance bundle of sticks, herein 'bundle' is collective noun.  

3. a modifying clause whose subject and/or verb is implied- elliptical clause

it is a clause in which words are being left out. on the other hand, the missing word is understood due to the logic or pattern of the sentence.  

4. two or more nouns and/or pronouns serving the same grammatical function and followed by a pronoun that references one or all nouns- compound antecedent

compound antecedent refers to which is made up of two or more words which are joined by 'or' or 'and.'

5. an adjective clause introduced by a pronoun- relative clause.

relative clauses are the clauses which begin with the relative pronouns such as when, where, which, that or who. the noun that precedes, relative pronouns identify or define that noun.  

6. the word, phrase, or clause to which a pronoun refers- antecedent.

antecedents refers to the phrases, clauses or words which are replaced with one of the third personal pronouns.

what were the options?