"Thinking is mental activity in its cognitive aspect." Whose definition of thinking is this one? [UPTET-2014-II]

"Thinking is mental activity in its cognitive aspect." Whose definitio

1.	"Thinking is mental activity in its cognitive aspect." Whose definition of thinking is this one? [UPTET-2014-II]
A.	Warren
B.	Ross
C.	Valentine
D.	Skinner
Answer» C. Valentine