Answer: Option B
The given sentence is in the present continuous tense, which indicates an action in progress at the moment of speaking. The sentence is correctly expressing that the numbers of tourists are currently increasing. However, the sentence can be made more effective and meaningful by using appropriate verb tense.
Option A, "has increased by leaps and bounds," is in the present perfect tense. This tense is used to describe completed actions that have a connection to the present moment. The use of this tense would be incorrect in the given sentence since the sentence is talking about the current increase in the number of tourists.
Option B, "increases by leaps and bounds," is in the present tense. This tense is used to describe actions that are happening in the present moment. This option correctly conveys the message that the numbers of tourists are currently increasing.
Option C, "are increasing by leaps and bounds," is in the present continuous tense, which is the same tense as the original sentence. This option does not make any significant changes to the original sentence.
Option D, "increased by leaps and bounds," is in the past tense, which indicates that the action has already happened. This tense would be incorrect in the given sentence since the sentence is talking about the current increase in the number of tourists.
Therefore, option B, "increases by leaps and bounds," is the correct answer. It effectively conveys the message that the numbers of tourists are currently increasing, and it is in the correct tense.
In conclusion, when choosing the correct verb tense in a sentence, it is essential to consider the time frame in which the action is happening, whether it is past, present, or future. Using the appropriate verb tense helps to make the sentence effective and meaningful.