Does space in between have any significance in IUPAC nomenclature? The correct IUPAC name of the following compound is:

(a) 2,4,6-trimethyl cyclohexanone
(b) 1,3,5- trimethyl benzophenone
(c) trimethylcyclobutanone
(d) 2,4,6-trimethylcyclohexanone

I was confused between option (a) and (d). I opted for option (a), but our teacher told that ans is an option (d). The only difference I see between these two options is that there is space in (a). Does space have any significance in IUPAC nomenclature?
$\boxed{\textbf{d}}$ is correct. It is the standard IUPAC name.

However, "2,4,6-trimethyl cyclohexanone" will often be understood as 2,4,6-trimethylcyclohexanone, similar to how, in theory, neopentane, 2,2-methylpropane and 1,1,1,1-methylmethane are all equivalent.