If a person develops chronic swelling of the lymphatic vessels in the appendages and deformity of the genitals, which disease will the person have?

Assertion $A$: In elephantiasis, body parts like legs, arms, and genital organs swell significantly.
Reason $R$: In chronic cases, filarial worms block the lymphatic vessels.
Which option is correct for Assertion $A$ and Reason $R$?

Identify the correctly matched pair of the disease and its causative agent/vector.

Ascariasis is caused by an endoparasite of human $...A...$ commonly called $...B...$ Here $A$ and $B$ refer to:

Filariasis is caused by the infection of:

In the mosquito $Culex$ $fatigans$,how many days does the microfilariae take to develop into an infective larva?