Question

Which of the following could be evidence that an organism's growth is influenced by the organism's environment?
A breed of cattle can be made larger by breeding together only the largest cows and bulls.
Plants grow taller and more quickly when given the right amount of light and water.
Two different kinds of grass are grown in neighboring yards. One yard has to be mowed much more often than the other.
The average height of an oak tree in northern Texas is much less than the average height of the same kind of oak tree in northern Indiana.

Answer 1

Items 2 and 4.

2 (plants grow taller with the right light and water) directly shows growth changing with environmental conditions.
4 (the same oak species is much shorter in Texas than in Indiana) suggests climate/environmental differences affect growth.

1 is selective breeding (genetic change), and 3 compares two different grass species (genetic differences), so those do not by themselves show environmental effects.