What's missing from the following sentence? The sparkling blue bicycle with the brand new tires and comfortable seat. A. A predicate B. A subject C. A modifier D. A colon

What is missing from this sentence is A. a predicate. We have the subject - as a matter of fact, the whole sentence is a subject that needs to be finished somehow - and the way to finish this phrase is by adding a predicate in order to make it a sentence. A group of words where there is no predicate is just a phrase - it is not a sentence.