Regarding point source epidemic, false statement (s) is/are:a) Rapid rise & fallb) Only infectious disease can causec) Explosived) Cases occur even after incubation periode) No secondary wave: (A) ce, (B) bd, (C) cde, (D) eb
Answer is B. Features of point source (single exposure) epidemics 

The exposure to the disease agent is brief and essentially simultaneous → single exposure.
Because disease agent enters into all exposed persons at same time → the resultant cases all develop within one incubation period of the disease.
The epidemic curve rises and falls rapidly.
Because exposure is single (simultaneous) with no further exposure → No secondary wave (no secondary case).
Epidemic tends to be explosive, there is clustering of cases within a narrow interval of time.
Point source epidemics are mostly (not always) due to exposure to an infectious agent.
Examples → Food poisoning, Bhopal gas tragedy, Minamata disease in Japan, Chernobyl tragedy.