Which of the following are true with respect to the concept of underemployment?

1. Workers are employed in roles that do not utilize their skill sets effectively.

2. Workers are in low-paying jobs relative to their qualifications and abilities.

3. Part-time workers who voluntarily choose part-time jobs are considered underemployed.

4. Labour productivity tends to be low due to mismatch between job roles and worker capabilities.

Select the correct answer using the code given below: