in reported speech "it" is changed into "that"

customer-:can i have a bottle of juice?

shopkeeper:-sorry,we have only milk bottles

c:-when will it be available?

s:-i can give it to you tomorrow.

change into indirect

the customer asked the shopkeeper(a)-------

the shopkeeper apologized and said(b)--------

the customer wanted to know(c)------------

i have doubt in (c)

according to me its answer is

when it would be available