Under federal law, pacs can contribute no more than per candidate for federal office for a primary election and general election combined

The answer is $5,000.  Traditional PACs have a $5,000 per person limit on contributions and cannot receive money from companies or unions. Regular PACs may donate straight to a politician or political party. This is different from super PACs, they are restricted to spending autonomously of such promotions.

this null effect is caused by a weak manipulation and ineffective internal validity. in a scientific study, as the one dr. morimoto is trying to perfom, internal validity refers to the confidence placed in the cause-effect relationship and to how well an experiment is done and able to eliminate confounding variables.        

i'd have to with d.

explanation: