Which species is a Lewis acid but not a Brønsted–Lowry acid?

CHEMISTRY · Single correct · A Level · Chemistry · Acids and bases · Acids and bases

Problem

Which species is a Lewis acid but not a Brønsted–Lowry acid? (1)

\text{Fe}^{3+}

(2)

\text{CH}_3\text{OH}

(3) Fe (4)

\text{NH}_3