The correct answer is B) he received threats, abuse, and harsh treatment, even within his own team.
The statement that best describes the initial reaction to Jackie Robinson’s breaking of the color line in professional baseball is "he received threats, abuse, and harsh treatment, even within his own team.
On April 1947, Jackie Robinson became the first black player to sign a contract with a Major League Baseball Club, Branch Rickey was the General Manager of the Dodgers and risked his reputation in the League and was brave enough to sign Robinson, an excellent athlete and baseball player. Of course, many people disapproved the idea even inside the team.
The other options of the question were A) He was welcomed enthusiastically nearly everywhere and C) It when without hardly any notice among other players and fans.