Suppose x $=("$Bursa$"$:$16,$ "Istanbul":$34,$ "Yalova":$77),$ to

delete the entry for "Bursa" what command do we use?

a$.$ del $("$Bursa$"$:$30)$

b$.$ del $["$Bursa$"]$

c$.$ x$.$delete$("$Bursa$"$:$30)$

d$.$ x$.$delete$("$Bursa$")$