Fact 1: Bacteria in soil convert atmospheric nitrogen into a form usable by plants. Fact 2: Plants have to have nitrogen to grow. Given the two facts above, what do plants need to grow?

Choose from:
[1]. energy.
[2]. sunlight.
[3]. nutrients.
[4]. bacteria.
[5]. lifting.
[6]. Energy..
[7]. muscle.
[8]. darkness.
Answer:
[4].