GMAT Sentence Correction (SC) | Re: George Brown lost more than 180 pounds since having an

George Brown lost more than 180 pounds since having an operation truncating his stomach three years ago.

a)lost more than 180 pounds sincehaving
having is continuous . wrong.

b)lost more than 180 pounds since havinghad
having had is wrong construction.

c)has lost more than 180 pounds since
straight forward. simple. CORRECT

d)has lost more than 180 pounds after
has..since.
he has not lost that weight immediately after the operation.
it has been an ongoing process. so, has lost....since
...

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