Q1. Choose the most appropriate option to fill in the blanks: I _________ her _________ a long time, _________ she was a child.
A know, since, for
B knew, x, since
C have known, for, since Correct
D was knowing, since, since
Explanation
The sentence needs the present perfect, because the relationship began in the past and continues up to the present: “I have known her.” A duration such as “a long time” takes “for”, while a starting point or reference time such as “she was a child” takes “since”. “Know, since, for” reverses the prepositions and uses the wrong tense. “Knew” suggests only a past relationship and leaves the duration phrase unsupported. “Was knowing” is not idiomatic here, and “since a long time” is incorrect in standard English.