To solve this question, the user needs to have an understanding of the comparative forms of adjectives.

Now, let's go through each option and explain why it is right or wrong:

A. The option is incorrect because it uses the wrong comparative form of the adjective "competent". "Less competent" should be used instead of "the less competent".

B. The option is correct. It uses the correct comparative form of the adjective "competent". "Least competent" means "the smallest amount of competence" or "the lowest level of competence".

C. The option is incorrect because it uses a non-existent superlative form of the adjective "competent". "Competentest" is not a valid word in English.

D. The option is incorrect because it uses two comparative forms of the adjective "competent" in the same sentence. It should be "less competent" instead of "lesser competentest".

Therefore, the correct answer is:

The Answer is: B. the least competent.