A Worker Was Observed for Four Cycles of a Repetitive

A worker was observed for four cycles of a repetitive task.The observer used the continuous method for recording the times.The continuous times (in seconds) for each element are:
$$\begin{array} {r } { \text { Cycles } } \quad \quad \quad \\\begin{array} { | l | c | c | c | c | } \hline \quad \text { Element } & 1 & 2 & 3 & 4 \\\text { 1. Pick up nut \& bolt } & 2 & 12 & 25 & 39 \\\text { 2. Thread nut onto bolt } & 5 & 16 & 29 & 42 \\\text { 3. Pick up wrench } &7 & 18 & 32 & 43 \\\text { 4. Tighten bolt, lay wrench } &11 & 23 & 38 & 48 \\\text { aside } & \\\hline\end{array}\end{array}$$
Which one of the following are the "select times" ( $\bar{t}$ ) for each element? The first number is the select time for the first element,the second number is the select time for the second element,and so on.

A) 19.5, 23, 25, 30
B) 1.5, 3.5, 5, 2
C) 2, 3, 2, 5
D) 1.5, 3.5, 2, 5