Phosphate esters can have one or more

R

groups, and these

R

groups can be different.\ Which of the following depicts a phosphate ester in which one R group is a methyl group, a\ second

R

group is an ethyl group, and the last hydroxyl group is deprotonated?\ A\ B\ C\ D\

E

\ F\ Compound A\ Compound B\ Compound C\ Compound D\ Compound E\ Compound F