Carrot roots become longer

Answer: Option B

Carrot roots become longer below 10°C temperature.
The carrot is a root vegetable and biennial plant in the umbellifer family, Apiaceae. It grows a rosette of leaves while building up the enlarged taproot.
The shape and size of carrot roots are influenced by soil type, temperature, etc. branching in carrots due to hereditary and the presence of under-composted organic matter or injury to the tap root system or check in heavy soil at a lower temperature.