Select the most appropriate option to fill in the blank.
The police will regard it as an accident ______ any evidence to the contrary is found.

Options

A. whenever
B. still
C. otherwise
D. unless

Explanation

‘Unless’ means ‘except if’ or ‘if not’. It is a negative conditional conjunction which is generally used to describe two conditions(negative sense) together like unless you work hard, you cannot (negative) achieve success. Hence, unless will be the most appropriate answer.