What suffix turns 'care' into an adjective meaning full of care?

• A. -less
• B. -ful
• C. -ish
• D. -ous

Answer: (B)

Suffixes that mean "full of" attach to a base word to describe a quality the noun has. When -ful is added to care, you get careful, an adjective that means full of care or showing care and caution. That’s why careful is the natural word to describe someone who is thoughtful and careful in what they do. Other endings change the meaning in different ways: -less means without, so careless would be without care; -ish suggests “somewhat like” and isn’t the right fit for this base; -ous makes a different type of adjective and isn’t the standard form to express “full of care.” So -ful is the correct suffix.