The correct option is C Assertion is correct but Reason is incorrect.
Connective tissue contains loosely spaced cells, which are embedded in rigid, jelly like, fluid matrix. So, there are less cells present in connective tissue. Most of the part of the connective tissue is made of matrix, which contains proteins, sugars, fibers, salts, some compounds, etc.
Intercellular substances i.e. matrix is made of many different types of materials as, proteins and sugars (cartilage); proteins, salts, hormones (blood); calcium and phosphorous compounds (bone).