Seeds that are planted upside down are still able to grow into mature plants. Which explanation best explains this phenomenon (a)The roots change into branches in the branches turn to roots(b) The roots grow towards the force of gravity and the stem goes away(c)The plant will become a smaller version of a mature plant(d) roots always grow toward the dark and the stem grows toward the light

b) The roots grow towards the force of gravity and the stem goes away

Explanation:

The parts of a plant can be divided into shoot and roots. The root of the plant is the part that grows below the ground surface in order to anchor the plant. When a seed germinates, the root part of that seed grows towards GRAVITY i.e exhibits geotropism while the shoot part grows away from gravity i.e. upwards.

Hence, if a seed is planted upside down, it will still grow into an erect mature plant because THE ROOT WILL ALWAYS GROW DOWNWARDS IN RESPONSE TO GRAVITY (positive geotropism) while the stem grows upward away from gravity (negative geotropism)

the answer is:

carbon dioxide