[sapta]

Ethoxyethane is an IUPAC name (R.5.5.4.1)
Diethyl ether is an IUPAC name (R.5.5.4.2)
3-oxapentane is an IUPAC name (R.5.5.4.3)

what is the IUPAC name of CH₃CH₂OCH₂CH₃?

A.Ethoxy ethane
B.Di ethyl ether
C.3-oxapentane
D.Methoxy butane

This question is given in a book.the first three options are all correct.So,which one is wanted?

If the question is EXACTLY as you typed it, then only C is the right answer.  "Ethoxy ethane" should NOT have a space in it and "Di ethyl ether" should only have ONE space in it.

If the options are exactly as I typed them above, then A, B and C are all acceptable.

D is just plain wrong.

the question was ,in fact, given in another language(not English).I had to translate it and couldn't give proper attention to the number of gaps.In our language the gaps are not given enough importance which is no doubt wrong.So,considering the options to be those you typed first(the correct ones),which option is most acceptable- Diethyl ether,Ethoxyethane or 3-oxapentane?One thing I inform you is that Diethyl ether is NOT considered an IUPAC name in our books.
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thanks for noticing the wrong number of gaps.You got a great solution to my 'wrongly set' question

[Albert]

In my opinion, I repeat, the best answer is ethoxyethane.

Mind you, what was the original language?

[xiankai]

sheesh... sounds like nit-picking on spelling 

I don't mean to be a jerk, so sorry if it sounded that way.

I just figured that when there are three seemingly 'right' answers, there must be a trick stuck in somewhere.

i meant the way it was the book who posed the question in such a way, sorry 

it jsut reminds me of a question where the paper asked which formula for deuterium compounds was wrong; i tried to look for problems in the nomenclature, but in the end it was actually the missing of a subscript that made a particular compound wrong; it irks me that the books try to nitpick on small details quite unrelated to the original topic.

[sapta]

In my opinion, I repeat, the best answer is ethoxyethane.

Mind you, what was the original language?

The language was Bengali.I hope you have heard its name.Anyway,I also think Ethoxyethane is the best answer.Thanks,all of you

[Albert]

I may try to impress you saying I can speak Bengali fluently...but it'd be a lie.

[mrdeadman]

i thought it was an ether, an O bonded between 2 carbons. i can't ever remember any of those organic names.