Step 1: Sentence (A).
“He _____ the television when the bell rang.”
An action in progress interrupted by another action requires Past Continuous Tense.
\[
(A)\rightarrow(IV)\ \text{was watching}
\]
Step 2: Sentence (B).
“I _____ this movie already.”
The word “already” indicates Present Perfect Tense.
\[
(B)\rightarrow(III)\ \text{have watched}
\]
Step 3: Sentence (C).
“The police teams are on duty to _____ over his whereabouts.”
After “to”, base form of verb is required.
\[
(C)\rightarrow(I)\ \text{watch}
\]
Step 4: Sentence (D).
“At this time tomorrow, you will be _____ the cricket match in London.”
Future Continuous Tense requires present participle.
\[
(D)\rightarrow(II)\ \text{watching}
\]
Thus,
\[
(A)-(IV),\ (B)-(III),\ (C)-(I),\ (D)-(II)
\]
\[
{\text{Option (B)}}
\]
