Final answer:
Yes, there was evidence of pay discrimination in the NFL, MLB, and NBA in the 1970s and 1980s.
Step-by-step explanation:
In the 1970s and 1980s, there was evidence of pay discrimination in the NFL, MLB, and NBA. Women and people of color in these leagues were often paid less than their white male counterparts. This can be seen in the significantly lower average salaries of players from marginalized groups during that time period.
For example, in the NFL, black players were paid less on average compared to white players. In the MLB, Hispanic players faced similar pay disparities. In the NBA, black players also experienced lower salaries compared to white players.
Therefore, the correct answer to the question is a) Yes, in all three leagues, as evidence suggests pay discrimination was present in the NFL, MLB, and NBA during the 1970s and 1980s.