Define \(R_n\) to be the maximum amount earned by cutting a rod of length n…

Define $R_n$ to be the maximum amount earned by cutting a rod of length n meters into one or more pieces of integer length and selling them. For $i > 0$ , let  $p[i]$ denote the selling price of a rod whose length is i meters. Consider the array of prices:

$\text{p}[1]=1,\text{p}[2]=5,\text{p}[3]=8,\text{p}[4]=9,\text{p}[5]=10,\text{p}[6]=17,\text{p}[7]=18$

Which of the following statements is/are correct about $R_7$ ?