Which of the following is true about total factor productivity (TFP)?

A) it can be measured just like capital and labor
B) it cannot be directly measured so it has to be calculated from given values of capital, labor and output
C) while it cannot be measured directly, it has an exponent of 0.3 in the Cobb-Douglas production function
D) while it cannot be measured directly, it has an exponent of 0.7 in the Cobb-Douglas production function
E) none of the above

B