My mother is a shrewd businesswoman.

Analyze the question: You are asked for the word opposite in meaning (an antonym) to "shrewd" in the sentence "My mother is a shrewd businesswoman."

Explain the concept: Shrewd means clever, sharp-witted, and having good judgment, especially in business or money matters. It describes someone who is not easily fooled and who makes smart decisions. So we need a word that means foolish, easily deceived, or lacking good judgment.

Step-by-step solution:

• A. reliable means dependable. This is not the opposite of shrewd. A person can be both reliable and shrewd.
• B. resourceful means able to find clever ways to solve problems. This is close to shrewd in meaning, so it is a synonym and not an antonym.
• C. orderly means neat, organised, or well-behaved. It has no direct link to shrewdness in either direction.
• D. gullible means easily tricked or fooled. A gullible person lacks the sharp judgment of a shrewd person, so this is the true opposite.

Answer: The correct option is D. gullible.

Tip: In antonym questions, first work out the meaning of the underlined word. Then remove any options that are synonyms, since examiners often include one as a trap (here, resourceful). Remember: shrewd = sharp, gullible = easily fooled.