Answer: option c
Sieve tubes element are use to transport sugars through out the plants.
Step-by-step explanation:
Sieve tubes element are elongated and specialised living cells found in the phloem of a flowetlring plant.
They help the phloem to function very well.
Their main function is to transport carbohydrates especially sucrose in the plants. E.g transporting of sucrose from leaves to the fruits.