According to john holland's personality type theory, people who are down to earth, practical problem solvers, and physically strong, but who have mediocre social skills, are best described as

a) conventional
b) enterprising
c) realistic
d) intellectual

Option C

Explanation:

John Holland's Personality type theory classifies people on the basis of the 6 personality types which are realistic, artistic, investigative, social, conventional and enterprising.

Out of these 6 personality type the one describing the the traits in the question are that of a realistic type personality.

Realistic type personality is one which depicts an individual as practical, independent, strong, can easily deal with the problems of the physical world, conservative, down to earth.