Based on APA style, what is wrong with the following reference?

Karau, Steven. J., & Williams, Kenneth. D. (1993).

Social loafing: A meta-analytic review and theoretical integration. Journal of Personality and Social Psychology, 65, 681-706.

a. The name of the journal should be underlined.

b. Only the initials for the authors’ first and middle names should be used.

c. The first letters of the words in the title of the paper should be capitalized.

d. Nothing is wrong with the reference.