He talked as if he---everything.
A
has known
B
had known
C
knows
D
knew
Correct Answer: had known
As if দ্বারা যুক্ত দুটি অংশের প্রথম অংশটি past indefinite হলে দ্বিতীয় অংশটি past perfect tense হয়। সুতরাং সঠিক উত্তর হবে - had known.