Pick from:
(1). during the day.
(2). it can be seen.
(3). gastropod shells.
(4). Laying eggs.
(5). litter.
(6). aerobic capacity.
(7). mechanical.
(8). electrically.
Given those answer options, answer the question: Fact 1: Monotremes are mammals that reproduce by laying eggs. Fact 2: Echidnas are monotremes, or egg laying mammals. Given the two facts above, how does an echidna reproduce?
A:
(4).