The very small stone tools, often fixed into handles of bone or wood, used by people of the Mesolithic period are called:

Microliths are tiny stone tools, usually about 1 to 5 centimetres long, which were typical of the Mesolithic period (Middle Stone Age).

About microliths:

• "Microlith" comes from the Greek words "mikros" (small) and "lithos" (stone).
• They were usually made from fine-grained stones, such as chert, chalcedony, agate, jasper and quartz.
• They come in many geometric shapes, such as triangles, crescents (lunates), trapezes and points.
• Because they were so small, they were not used alone; they were fixed into handles of bone or wood with gum or resin, to make composite tools such as arrows, spears, sickles and knives.
• The use of bows and arrows with microlith tips made hunting of small and fast animals easier.

About the Mesolithic period:

• In India, it began roughly 12,000 to 10,000 years ago, when the climate became warmer after the last Ice Age, and lasted until the beginning of farming, which happened at different times in different regions.
• Grasslands spread, and animals such as deer, antelope, goat, sheep and cattle increased.
• People were still mainly hunter-gatherers, but some began to domesticate animals and collect wild grains.
• They lived in rock shelters, caves, and open sites near lakes and rivers.
• Some Mesolithic people buried their dead with care.
• Rock paintings of hunting and dancing scenes are associated with this period.

Comparison of stone tools:

• Lower Palaeolithic: handaxes and cleavers.
• Middle Palaeolithic: flake tools such as scrapers.
• Upper Palaeolithic: blades and burins.
• Mesolithic: microliths.
• Neolithic: polished stone axes (celts).

Why not the other options?

• ✗Handaxes and cleavers are large tools of the Lower Palaeolithic.
• ✗Celts are polished stone axes of the Neolithic.