The new drug proved to be highly effective, it has no side effects
a) properly constructed sentence
b) comma splice
c) lacks parallel parts
d) dangler
b) comma splice.
The sentence joins two independent clauses with only a comma. To correct the error, a conjunction should be added after the comma or the two clauses should be separated into distinct sentences, like this:
The new drug proved to be highly effective, and it has no side effects.
or
The new drug proved to be highly effective. It has no side effects.
a) properly constructed sentence.
Explanation: The sentence is grammatically correct and conveys a clear message. It states that the new drug has proven to be highly effective and also mentions that it has no side effects. It does not contain any errors such as a comma splice, lack of parallel parts, or a dangler.