**Core Concept**
The life span of a mosquito is a critical factor in understanding the transmission dynamics of various vector-borne diseases. Mosquitoes undergo a complex life cycle, including egg, larva, pupa, and adult stages, with different durations for each stage. The adult stage, which is responsible for feeding and transmitting diseases, has a relatively short life span.

**Why the Correct Answer is Right**
The correct answer, **2 weeks**, is based on the life cycle of the mosquito. Adult mosquitoes typically live for 2-4 weeks, with some species living up to 6 weeks. During this period, they are capable of feeding multiple times, which increases the risk of disease transmission. The short life span of mosquitoes is a key factor in understanding the epidemiology of vector-borne diseases, such as malaria, dengue fever, and Zika virus.

**Why Each Wrong Option is Incorrect**
**Option A:** 1 week is an underestimation of the life span of an adult mosquito. While some mosquitoes may live for only 1 week, others can live for up to 4 weeks.
**Option C:** 1 month is an overestimation of the life span of an adult mosquito. While some species may live for up to 6 weeks, 1 month is not a typical life span for adult mosquitoes.
**Option D:** 1 year is an extremely long life span for an adult mosquito. Adult mosquitoes typically do not live for more than 6 weeks.

**Clinical Pearl / High-Yield Fact**
It is essential to note that the life span of mosquitoes can vary depending on factors such as temperature, humidity, and availability of food. Understanding the life cycle and life span of mosquitoes is crucial for developing effective strategies for disease control and prevention.

**✓ Correct Answer: B. 2 weeks**