C. skunks
I think thats the answer because its talking about the skunks in general.
I believe the answer is es.
Let's define these types of clauses. Adjective clauses can serve as a multi-word adjective, basically. Noun clauses can serve as a multi-word noun, with a subject and verb, but remember, they are still dependent. Adverb clauses start with a subordinating conjunction. Now let's dissect this sentence.
"It is not right" independent clause
"to make a promise" adjective clause
"unless one is sure he can fulfill the promise" adverb clause
the answer is "one adverb clause and one adjective clause"
I think the word with should be replace with the word for.
I would hate it if I wasn't able to do this ....... I would be ecstatic to help out with this task