The answer is going to be D!
Riding a skateboard is a phrase
A phrase can not have verb and subject together. riding a skateboard doesn't have subject. the others are clause.they have both subject and verb.
good luck.
Answer:
The conscience refers to a state of awareness or a sense that one's actions or intentions are either morally right or wrong, along with a feeling of obligation to do the right thing. ... You should decide what to do according to your own conscience...
