Communication that used to assign goals to sub-ordinates in an organisation, is called

Goals handed down to subordinates travel from a superior to a junior, which is the defining feature of downward communication. Instructions, job assignments, targets, policies and feedback all move along this vertical line from higher to lower levels of the hierarchy.

Why the other options fail:

• Upward communication runs from subordinates to superiors, such as progress reports, suggestions, grievances and feedback on targets.
• Informal communication travels outside the official chain of command, usually through the grapevine, so it is not defined by who reports to whom.
• Lateral communication happens between peers at the same level, for example between two departments coordinating a project.

The concept sits in the classic classification of organisational communication flows, which also connects to Fayol's scalar chain and to Management by Objectives, where goals are set and cascaded down. For Mains, this matters in governance questions on accountability and delegation: targets flow down, but feedback must flow up for the system to work.

Trap: aspirants see "goals" and pick upward communication, because in MBO subordinates participate in setting targets. But the question asks about the assignment itself, which is a downward act.