Consider the following statements and select the correct answer from the codes given below:
Assertion (A): In filariasis, the lower legs and scrotum are swelled to unproportionate level
Reason (R): The filarial worms block the lymph vessels and lymph node.

Options

A. Both A and R are true and R is the correct explanation of A.
B. Both A and R are true, but R is not the correct explanation of A.
C. A is true, but R is false.
D. A is false, but R is true.

Answer

A

Explanation

Lymphatic filariasis is caused by nematodes of genera, Wuchereria bancrofti, Brugia malayi and Brugia timori, which occupy the lymphatic system, including the lymph nodes. In chronic cases, the worms lead to disease elephantiasis in which legs and sometimes genital organs swell up.