Although natalie receives somewhat greater rewards from her marriage than does her husband, both are satisfied with the relationship because they each benefit in proportion to what they put into it.
this best illustrates the significance of:

a. equity.
b. deindividuation.
c. social facilitation
d. the mere exposure effect.

a. equity

Explanation:

Equity theory -

The equity theory was given by J. Stacy Adams , back in the 1960's .

The theory of equity focus on the distribution of the resources  , that whether their is equal distribution of resources or not , between the two people , is known as equity theory .

The equity measurement is done by comparing and contrasting the portion of the contributions and the benefits of both the person individually .

The same scenario of equity theory is given in the question .

fir trees are found in areas with cooler climates. fir trees have needles for leaves and remain green year-round.