Explain the answer. Then test the idea.

javac compiles Main.java. java Main then runs the compiled class.

The integer division produces 2 first. Assignment then converts it to 2.0.

The validity condition excludes values over 100, and the pass boundary includes 40.

Reference assignment does not invoke new or duplicate the underlying object.

The runtime object selects the overridden instance method.

Both concrete objects implement Greeting and can be used through that shared type.

The contract rejects non-positive amounts before changing state.

A map associates at most one value with an equal key.

It removes the last element returned by next and cannot be repeated for the same return.

Parsing checks integer representation and range, not the application's 0–100 mark rule.

ORDER BY defines the final ordering. A table's apparent insertion order is not a query guarantee.

HAVING evaluates the aggregate condition for each completed group.

The unmatched right-side course_id is NULL, and COUNT(column) excludes null values.

COUNT(*) counts rows whether or not city is present.

A NULL CHECK result does not by itself reject the row; NOT NULL enforces presence.