Final answer:
The force that can push the block upward is Tension force.
Step-by-step explanation:
The force that can push the block upward is Tension force. Tension force is a pulling force that can be exerted by a string, rope, or cable. It acts in the direction away from the object and can lift objects vertically, including blocks. When a block is suspended by a string or rope, the tension force in the string or rope is responsible for lifting the block upward.