Step 1: Understand the correct demonstrative.
"These" is the correct demonstrative adjective for referring to specific, countable things close in time or place. Since flowers are countable and the speaker is referring to them specifically, "these" is the correct choice.
Step 2: Analyze each option.
- (A) them: Incorrect. "Them" is an object pronoun, but we need a demonstrative adjective here.
- (B) these: Correct. "These" is used to specify plural, countable things close to the speaker.
- (C) him: Incorrect. "Him" is a pronoun for a male, and does not fit in this context.
- (D) their: Incorrect. "Their" is a possessive pronoun, but we need a demonstrative adjective.
Step 3: Conclusion.
The correct word is "these." The sentence should be "I bought these flowers for my mother."