The Economy Has Grown by 4% Per Year Over the Past

The economy has grown by 4% per year over the past 30 years.During the same period,the labour force has grown by 1% per year and the quantity of physical capital has grown by 5% per year.Each 1% increase in physical capital per worker is estimated to increase productivity by 0.4%.Assume that human capital has not changed during the past 30 years.How fast has physical capital per worker grown?

A) 5%
B) 4%
C) 3%
D) 2%