Assertion: The current flowing through each resistor is the same when connected in series.
Reason: The voltage drop across each resistor remains the same when connected in parallel.

According to ohms law

when resistors are connected in series then the current is constant because the current flowing in the whole circuit is the same 

when resistors are in parallel connection then voltage across the circuit is the same 

but here in this question assertion and reason are giving two complete different statements each are not related, hence we can conclude that option B is the correct answer