In this grammar, the operator with the highest precedence is the negation operator 'not'. Option D
In the provided grammar for logical expressions, the highest precedence operator is the negation operator "not".
The grammar rules indicate that the symbol 'a' can be a logical expression containing 'not a'.
As per the grammar, 'not' is applied directly to 'a', '0', or '1'. This implies that the negation operation has the highest precedence because it directly operates on the atomic propositions 'a', '0', or '1', altering their truth values before other logical operations like 'and', 'or' are performed.