\\\\(\ ext{We need to find the HCF or GCD that is Greatest Common Divisor}\\\\) \\\\({120 = 2\ imes2\ imes2 \ imes3\ imes5}\\\\)\\\\({180 = 2\ imes2\ imes3\ imes3 \ imes5}\\\\)\\\\({240 = 2\ imes2\ imes2\ imes2\ imes3\ imes5}\\\\)\\\\({GCD = 2\ imes2\ imes3\ imes5= 60}\\\\)\\\\(\ ext{The greatest capacity = 60 liters}\\\\)\\\\(\ ext{So the merchant needs to fill 60 liters of all types of oils }\\\\)\\\\(\ ext{Hence option C is correct}\\\\)