Hello,

and B) chacha as bihari ke bhai (Ramesh * Indra) ka beta davender and yogender hein. bhai ka beta h issiliye chacha hoga. Agar behen ka beta hota to mama hota. ( Trick to remember).

Pita to kabhi nahi hoga and bhai b nahi hoga !

Hope it helps!

Answer hain Chacha. Ramesh and Bihari are two brothers.
Ramesh's wife is Indra. Indra's son is Davender and Davender and Yogender are brothers (means Yogender also is Ramesh's son) . So, Bihari, being the brother of Ramesh is Uncle (chacha) of son of his brother, i.e. of Yogender and Davender