Match the sentences with the correct verb complement options.

Here are the correct matches for each sentence:

• 1. People ______ in the streets during the carnival.

  • The most suitable verb complement is "were dancing" (b).
  • Match: 1b

• 2. Children ______ costumes at the Halloween party.

  • The most suitable verb complement is "were wearing" (d).
  • Match: 2d

• 3. The band ______ sad songs at the wedding.

  • "The band" is treated as a singular unit, and "wasn't playing" (e) is the only singular option.
  • Match: 3e

• 4. Guests ______ photos during the birthday celebration.

  • The most suitable verb complement is "were taking" (c).
  • Match: 4c

• 5. Families ______ food for the festival.

  • The most suitable verb complement is "were preparing" (a).
  • Match: 5a

Combining these matches, we get: 1b, 2d, 3e, 4c, 5a.

This corresponds to the last option provided.

The final answer is $\text{1b, 2d, 3e, 4c, 5a}$.