Which are the assumptions of Signaling theory in Economic returns to higher education ?

(i) Individuals have different innate levels of productivity which is affected by Education.

(ii) Additional education incurs additional costs, which differ for high and low productivity workers.

(iii) There is asymmetric information with respect to worker’s productivity: individual workers know their skill level, but potential employer does not.

(iv) Schooling level can be observed without incurring a cost.

Select the correct answer from the options given below :