The answer is 2.
In a standing wave produced on a stretched string that is fixed at both ends, when the wavelength of the standing wave is equal to the length of the string, the number of nodes is equal to 2.
In a standing wave, nodes are points that remain stationary, and antinodes are points that undergo maximum displacement. When the wavelength is equal to the length of the string, there will be one node at each end of the string, and the entire string will vibrate in one complete loop. This creates a standing wave pattern with two nodes and one antinode.
I hope this helped!
~~~Harsha~~~