Which of the following sentences needs a semicolon to be correct?                 a.  jerry loves tennis he plays every day.      b.  if you ask me jerry is an incredible tennis whiz.      c.  playing tennis is lucy's favorite way to get daily exercise.      d.  lucy bought a new tennis racket and brought it home. 

A. Jerry loves tennis he plays every day.

Here, there is a need for a semi colon because there are two independent clauses (Jerry loves tennis, he plays every day) that need to be separated.

Hope this helps :)

1.restrictive clause - a clause not set off by commas that is necessary to the meaning of the word it modifies. The meaning of the sentence would be changed if we deleted it.
2. participle - verbal form used only as an adjective. Actually, present and perfect participles can also form multipart verbs, together with auxiliary verbs (e.g. I am waiting), but outside this role, they only function as adjectives (e.g. closed store, running water). When a present participle functions as a noun, it is called gerund.
3. infinitive - verbal form used as an adjective, adverb, or noun
4.adverb phrase - a prepositional phrase that modifies a verb, an adjective, or an adverb.
5.semicolon - joins two independent clauses if a conjunction is not used. Those two independent clauses, however, can normally function as two separate sentences.
6. gerund - verbal form used only as a noun. All gerunds end in -ing (e.g. Singing is my favorite activity.)
7.adjective phrase - a prepositional phrase that modifies a noun. Its headword is an adjective, and it functions as an adjective too - that is, it describes a noun.
8.direct address - directly speaking to someone
9.comma - sets off appositives. Appositives are noun phrases that modify a noun by renaming it, and they are always separated by commas (e.g. Marc, my longtime friend, will definitely come to the party.)
10.appositive phrase - a phrase that renames another noun or noun phrase. It can be short (e. g. a single word with an article), or long (a noun phrase with its own adjectives)