Consider the methods shown in the table below for making steel connections in the field. Do the following: a) With an MARR of 10%, determine which method is most economical, based on rate of return analysis. (2 pts.) Category By Hand Method A Method B Method C Production rate 5. 10 15 20 (LF/hour) Labor hours required (hours/month) 320 160 107 80 Annual labor cost (@ $8.10/hour) $2,592 $1,296 $867 $648 Annual power cost ($) 400 420 480 Initial investment ($) 4,000 6,000 7,000 Salvage value ($) 400 600 700 Service life (years) 20 20 20