Your answer is assassin acording to my teacher
The main clause is "Chris's chief interest was tennis".
The subordinate clause is "Which he was just learning to play" and it is an adjective clause because it describes what the "tennis" was like. Tennis is an object and this subordinate clause further describes that it is the tennis that he was trying to learn.
Scanning A. find specific info/names
The answer would be your third choice. Visualize means to see something so that is your answer
All of these are great answers but I like d. d is the best out of all the answers so far. picking d will give you that .5 to pass that class my friend