A state animal shelter had 4.2× 10^4 unwanted animals dropped off last year. If the goal of the shelter is to decrease the number by one-sixth this year, determine how many fewer animals will enter the shelter. Express your answer in scientific notation.
a) 3.5× 10^4
b) 4.0× 10^4
c) 4.3× 10^4
d) 4.7× 10^4