Place the following investment decisions in order from the lowest risk to the highest risk:

$1.($a$)$ purchase of replacement machinery

$2.($b$)$ new product in a foreign market

$3.($c$)$ new product in the local market

$4.($d$)$ repair of existing machinery

Why this option is not feasible?

Repair of existing machinery

Purchase of replacement machinery

New product in the local market

New product in a foreign market