The absolute threshold is the:
a. decreasing sensitivity to a stimulus over time.
b. intensity of a stimulus that can be detected in the presence of noise.
c. minimal intensity needed to just barely detect a stimulus.
d. minimal change in a stimulus that can just barely be detected.

C. minimal intensity needed to just barely detect a stimulus.

Explanation:

Absolute threshold is one of the most important terms in psychophysics and refers to the minimum threshold for a stimulus to cause a sensation.

In other words, the absolute threshold is the minimum amount of energy for a stimulus to be detected in at least 50% of attempts. The higher the absolute threshold, the lower the sensitivity to stimuli.

C. minimal intensity needed to just barely detect a stimulus.

Explanation:

one is through turgidity. this occurs before ground tissue ( collenchyma

and sclerenchyma cells) become well

developed to give structural support to the plant as it grows bigger. the xylem

tissue (composed of rigid tissue) of the young

plant render this support and also maintaining osmotic turgidity of the surrounding

plant cells.