Select the word segment that can substitute the bracketed word segment correctly and complete the sentence meaningfully.
The minister promised to provide free laptops to the public if his (party came in power).

To determine the correct substitute for the bracketed phrase "party came in power", let us analyze the sentence structure and context.

The sentence is: "The minister promised to provide free laptops to the public if his (party came in power)."

First, let's examine the tense of the sentence. The main clause uses the past tense "promised" to report a past promise: "The minister promised to...". The conditional clause expressing the condition under which the laptops would be provided needs to align grammatically and contextually. In standard English, the idiom for a political group achieving control of the administration is "to come into power" (with the preposition "into", not "in"). Thus, "came in power" is grammatically incorrect.

Second, we look at the meaning of the options provided to find the most appropriate and grammatically sound replacement:
1. "party loses the election": This contradicts the context of the minister's promise. A minister would promise free laptops if their party wins, not if they lose.
2. "he loses the election": This also contradicts the positive condition required for fulfilling the promise.
3. "party forms the government": This is grammatically correct and fits the context perfectly. "Forming the government" is the standard political expression for coming into power after winning an election.
4. "he comes to a party": This uses the word "party" in a social gathering sense, which is completely irrelevant to the political context of the sentence.

Therefore, replacing "party came in power" with "party forms the government" completes the sentence meaningfully and grammatically.

The correct answer is party forms the government.