A group effort of generating alternative ideas that can help a manager solve a problem is called.

The correct answer is D) Brain storming. Brainstorming is a group creativity technique popularised by Alex Osborn, where members put forward as many ideas as possible in a free, non-judgemental setting, and evaluation is deferred until idea generation is over. Its purpose is to widen the pool of alternatives before a decision is made, which is exactly what the question describes.

Why the others fall short:

• Delphi technique uses anonymous, repeated questionnaires to a panel of experts to reach consensus. Participants never meet face to face, and its aim is forecasting or consensus rather than idea generation.
• Out of the box thinking is a mindset of unconventional thinking. It is not a named group technique and can be practised alone.
• Nominal group technique is a structured decision-making method: members write ideas silently, share them in turn, then rank them. It is a group method, but its focus is prioritising ideas already generated, not generating them freely.

Core concept: group creativity and decision-making tools in the Management part of the syllabus, where the manager picks the right tool for each stage of problem solving. In Mains, this links to participatory decision-making in administration.

Trap: candidates pick Nominal group technique because it also sounds like a group method. Ask yourself whether the question is about generating ideas or ranking them.