Step 1: Understanding pollination.
Pollination is the process of transferring pollen from the male to the female reproductive organs of a plant. In Salvia and Cestrum, insects are the primary agents of pollination.
Step 2: Analyzing the options.
(A) insects: Correct — Both Salvia and Cestrum rely on insects, especially bees, for pollination.
(B) wind: Wind-pollinated plants have different characteristics, and Salvia and Cestrum are not wind-pollinated.
(C) bats: While bats pollinate certain plants, they are not the primary pollinators for Salvia and Cestrum.
(D) birds: Birds may be involved in some pollination, but not for Salvia and Cestrum.
Step 3: Conclusion.
The correct answer is (A) insects, as they are the primary pollinators for both Salvia and Cestrum.