In a packing plant, one of the machines packs jars into a box. A sales rep for a packing machine manufacturer comes into the plant saying that a new machine he is selling will pack the jars faster than the old machine. To test this claim, each machine is timed for how long it takes to pack 10 cartons of jars at randomly chosen times. Given a 95% confidence interval of (-6.85, 0.34) for the true difference in average times to pack the jars (old machine - new machine), what can you conclude from this interval?

a. We are 90% confident that the average packing time of the new machine is greater than the old machine. The sales rep does not appear to be telling the truth.
b. We do not have enough information to make a conclusion.
c. We are 90% confident that the difference between the two sample means falls within the interval.
d. We are 90% confident that the average packing time of the old machine is greater than the new machine. The sales rep appears to be correct.
e. There is no significant difference between the average packing time of the two machines. The sales rep does not appear to be telling the truth.