The main difference between the short run and the long run is that

a. the short run always refers to a time period of less than five years.
b. the long run always refers to a time period of one year or longer.
c. in the short run, some inputs are fixed and some are variable.
d. in the long run, all inputs are fixed.

The main difference between the short run and the long run is that " in the long run, all inputs are fixed "

Explanation:

Both inputs are variable in the long run while a total of one input is set in the short run.

For example, rent can be set short-term but long-termly differently.

The main difference between long-term and short-term expenses is that there are neither long-term fixed nor short-term influences.

In the long term, the overall price point, negotiated wages and aspirations are fully adapted to the state of the economy.

Depending on variable costs and the production volume, short-term costs are increasing or declining. If a company controls the short-term costs over time, then the expected long-term savings and goals are more likely to be accomplished.

first one

explanation:

answer; ///(d); determining who competes most closely   with whom evaluating whether industry driving forces and competitive pressure favor some strategic groups and hurt others, and ascertaining whether the profit potential of different strategic groups varies due to the strengths and weaknesses in each groups respective market positions;