Can clearance agent opt for presumptive taxation.

 I am engaged in the business of providing logistic service relating to export/import viz. transportation, warehousing, packaging, custom clearance.major area of activity is custom clearance which involves clearing of goods from docks/airports.Client pays me full amount out which I pay duties and transportation charges and remaining income is my income.can i opt for presumptive taxation under 44ad when filing income tax.