The number of alternatives and the way the claim is drafted does not really matter, and it should not depend on the examiner whether a restriction requirement is issued. The alternatives should be assessed from a technical standpoint, and restriction requirement should be issued when the following occurs:
There are two criteria for a proper requirement for restriction between patentably distinct inventions:
*(A) The inventions must be independent (see MPEP § 802.01, § 806.06, § 808.01) or distinct as claimed (see MPEP § 806.05 - § 806.05(j)); and
(B) There would be a serious burden on the examiner if restriction is not required (see MPEP § 803.02, § 808, and § 808.02).*
For purposes of the initial requirement, a serious burden on the examiner may be prima facie shown by appropriate explanation of separate classification, or separate status in the art, or a different field of search as defined in MPEP § 808.02
By way of example, you may claim 10 different alloys in one claim (or more claims) and not be forced to select a species if the alloys do not relate to different inventions and there is no serious burden on the examiner for examining the invention with each alloy, but be forced to restrict to one of two species if you claim two different features in two claims (or in one claim as in your example) that relate to different inventions or the examination of both different embodiments require searches in different classifications, for example.
Since you and your patent agent (if any) know your invention, you are the only ones able to determine whether the alternatives would fall in any of the two cases above.