You have four fixed-volume containers at stp. container a has 0.5 mol of gas in 11.2 l. container b has 2 mol of gas in 22.4 l. container c has 1 mol of gas in 22.4 l. container d has 2 mol of gas in 11.2 l. which of the four containers have equal pressures?

a. a and b

b. a and c

c. b and c

d. c and d