An Experiment Was Conducted to Compare the Mean Iron Content

An experiment was conducted to compare the mean iron content in iron ore pieces determined by three different methods: (1) mechanical, (2) manual, and (3) laser. Five 1-meter long pieces of iron ore were removed from a conveyor belt, and the iron content of each piece was determined using each of the three methods. The data are shown below. How should the data be analyzed?


$\begin{array} { l l l l } \hline\text { Piece}&\text { Mechanical}&\text { Manual }&\text { Laser } \\\hline 1 & 60.34 & 61.37 & 60.31 \\2 & 65.44 & 65.94 & 66.46 \\3 & 60.32 & 60.38 & 61.66 \\4 & 58.34 & 58.37 & 58.21 \\5 & 53.20 & 52.22 & 54.16 \\\hline\end{array}$

A) randomized block design with three treatments and five blocks
B) $3 \times 5$ factorial design
C) randomized block design with five treatments and three blocks
D) completely randomized design with three treatments