i dont understand these questions

Table 3.3

1) Using Table 3.3, what is the earliest expected time of completion of the whole project?

A) fewer than or equal to 21 days

B) greater than 21 but fewer than or equal to 22 days

C) greater than 22 but fewer than or equal to 23 days

D) greater than 23 days

2) Using Table 3.3, which activity is on the critical path?

A) Activity D

B) Activity F

C) Activity G

D) Activity K

3) Using Table 3.3, if the project is due to be completed in 28 days, what is the probability that the project will be completed on or before the due date?

A) less than or equal to 75%

B) greater than 75% but less than or equal to 85%

C) greater than 85% but less than or equal to 95%

D) greater than 95%

4) Using Table 3.3, if the project manager wants at least a 98% probability that the project will be completed on or before the due date, what is the shortest project due date that will satisfy the manager?

A) fewer than or equal to 28 days

B) greater than 28 days but fewer than or equal to 30 days

C) greater than 30 days but fewer than or equal to 32 days

D) greater than 32 days

\begin{tabular}{|c|c|c|c|c|} \hline Activity & ImmediatePredecessor(s) & MostOptimistic & MostLikely & Time(weeks)Pessimistic \\ \hline A & --- & 2 & 4 & 6 \\ B & -- & 1 & 4 & 7 \\ C & A & 2 & 2 & 2 \\ D & B & 1 & 7 & 10 \\ E & D & 2 & 4 & 6 \\ F & E & 1 & 2 & 3 \\ G & C & 3 & 4 & 17 \\ H & D,G & 3 & 7 & 11 \\ I & D & 8 & 9 & 10 \\ J & F,H & 4 & 5 & 6 \\ K & I & 1 & 1 & 1 \\ \hline \end{tabular}