Answer:
e) half
Step-by-step explanation:
as we know relation b/w charge(Q) , capacitance (C) and voltage (V) is
Q = CV ...........(i)
 we also know capacitance of a capacitor for separation d and area A is 
 C = ∈₀A/d ...........(ii)
 from the above equation it is clear that C  is inversely proportional to separation if separation doubled capacitance will reduced to half and from equation first charge is directly proportional to capacitance.
 that s why magnitude of charge will reduced to half 
so option (e) is right answer