When Samantha started working at her company, she felt sure she had nothing in common with her manager because he was much older than her. As she got to know him better, she realized that they had a very similar work ethic, and in fact shared many of the same hobbies. Samantha first judged her manager based on

a$.$ Physical and mental characteristics

b$.$ Deep level diversity

c$.$ Surface$-$level diversity

d$.$ Similarity$-$attraction phenomenon