$21.$ At December $31,2022,$ Jack Russell Ltd$.$ had $900,000$ common shares outstanding $($no preferred shares issued$).$ On September $1,2023,$ an additional $300,000$ common shares were issued. In addition, Jack Russell had $$10,000,000($par value$)6\%$ convertible bonds outstanding at December $31,2022,$ which are convertible into $600,000$ common shares. No bonds were converted in $2023.$ Net income for calendar $2023$ was $$3,750,000.$ Assuming the income tax rate is $30\%,$ the diluted earnings per share for $2023$ is

a$)$ $$2\mathrm{.}35.$

b$)$ $$2\mathrm{.}61.$

c$)$ $$2\mathrm{.}72.$

d$)$ $$3\mathrm{.}75.$