The denotation of a word gives the word's exact meaning, while the connotation of a word gives the word's emotional meaning.
Example:
Colors are a great example of connotative meaning and denotative meaning. For example, blue's denotative meaning is "of a color intermediate between green and violet, as of the sky or sea on a sunny day." But, blue's connotative meaning is sad or melancholy. You can say, "he is feeling blue", or "she looks blue" to express sadness.
"A. The ancestor of the dog." is a fragment. When in doubt, say the sentence out loud and ask yourself if there is enough information for the sentence to make sense.
If join is wants to work for a company that's eco-friendly, then he'd probably want to work for a company that recycles or uses reused materials. Something like that. Without seeing the Venn diagram, that's all the information I can give you.