To correctly answer this question, the user needs to understand the usage of semi-colons in sentences. A semi-colon is used to separate two independent clauses that are closely related in meaning. An independent clause is a group of words that can stand alone as a sentence.

Now, let's go through each option and determine which one requires a semi-colon.

A. Mumbai is a beautiful city with wide streets and sunshine.

This sentence does not require a semi-colon because "with wide streets and sunshine" is a prepositional phrase that is not an independent clause.

B. Delhi is a lovely city and roti is one of my favorite foods.

This sentence does not require a semi-colon because "and roti is one of my favorite foods" is a coordinating conjunction that connects two independent clauses.

C. I would love to go to Karnataka because Bangalore is a lovely city.

This sentence does not require a semi-colon because "because Bangalore is a lovely city" is a dependent clause that cannot stand alone as a sentence.

D. I would love to go to Tamilnadu ; I love temples.

This sentence requires a semi-colon because "I love temples" is an independent clause that is closely related in meaning to the first clause.

Therefore, the correct answer is:

The Answer is: D