Whorling whips are named so because of

The correct option is Mode of movement.

Explanation:
"Whorling whips" is a common descriptive name given to dinoflagellates, which are a group of unicellular eukaryotic microorganisms. The name is derived directly from their characteristic style of locomotion, or mode of movement.

Dinoflagellates typically possess two flagella (whip-like structures) with distinct orientations:

• One flagellum is longitudinal and acts as a steering rudder or provides forward propulsion.
• The other flagellum is transverse, wrapping around a groove (cingulum) in the cell body.

As these flagella beat, they cause the organism to spin and rotate around its axis as it moves forward. This distinctive, spinning or "whorling" swimming pattern resembling a spinning top is the reason why they are nicknamed "whorling whips". Thus, the name is based strictly on their mode of movement.