Answer the following question: Fact 1: Plants release oxygen during the day but not during the night. Fact 2: Oxygen from the air is needed by the body in order to live. Given the two facts above, what do plants do during the day but not during the night?

Pick from:
1). It helps them survive;
2). Help the body to live;
3). preventing heat transfer;
4). by making heat;
5). Generating heat;
6). converting electricity to heat;
7). Release energy;
8). adding heat;
Answer:
2).