The following data relate to work in the finishing department of a certain factory.Normal working day $8$ hoursBasic rate of pay per hour

Ksh$\mathrm{.}10$Standard time allowed to produce $1$ unit $5$ minutesPremium bonus payable at the basic rate $50\%$ of time savedOn a particular day one employee finishes $2400$ units. What is his gross pay for the day?

a$.$ Ksh$.146$

b$.$ Ksh$.80$

c$.$ Ksh$.140$

d$.$ Ksh$.60$