If a competitive firm is producing to the left of the minimum point of its longrun average cost curve

Question

If a competitive firm is producing to the left of the minimum point of its long-run average cost curve,

then

its profits will decrease if it builds a larger plant.

it can still be in long-run equilibrium as long as P = SRATC.

it can reduce its unit costs by building a larger plant.

it should shut down.

it cannot be producing its present output efficiently.

Microeconomics