Aside from Melipona bees, what other animal can pollinate vanilla?

Here is the question :

ASIDE FROM MELIPONA BEES, WHAT OTHER ANIMAL CAN POLLINATE VANILLA?

Here is the option for the question :

Lizards
Butterflies
Lemurs
Hummingbirds

The Answer:

And, the answer for the the question is :

Hummingbirds

Explanation:

[STC0011247]. Vanilla plants have tiny blossoms that only last a day. Because of this, it has a far smaller pool of potential pollinators to choose from than the average bloom. Hummingbirds and a few species of little bees, such Melipona and Euglena bees, are the only other pollinators. Naturally pollinated vanilla plants in the wild only have a success rate of about 1%.