Each SBU pursues its own distinct mission and often develops its own plans indepenently

True, each SBU pursues it's own distinct mission and often develops it's own plans independently

Explanation:

A Strategic Business Unit refers to a fully functional unit of a business which operates independently and like a fully functional business has it's own departments which act independently from the business to which an SBU reports.

Often, companies which produce multiple different products gradually set up an SBU for those products which have successfully created a distinct identity, separate from the main company.

The purpose of setting up an SBU is for better tracking of revenues and costs associated with the SBU.

So each SBU has it's own distinct mission i. e it's objectives and how (ways by which) it shall achieve those objectives. The plans for achievement of such objectives are devised accordingly.