IMO E-Additive Phrases cannot create plural subjects so if the subject is singular then it will remain singular.
In the above question the subject is "S dance and T dance" Compound Subject which is plural. Hence we require plural constitute after the comma and not constitutes. (A) The Sri-NuanSri-Nuan dance and Teut-Teung dance are an inherent part of Thai culture, and
along with others such as The Farmer's Dance, developed by the Ministry of agriculture, constitutes the main dramatic art form of Thailand - Subject Verb Error S and T dance is plural and Constitutes is Singular. The phrase Along with is an additive phrase / a modifier.
(B) The Sri-NuanSri-Nuan dance as well as Teut-Teung dance
are an inherent part of Thai culture, and along with others such as The Farmer's Dance, developed by the Ministry of agriculture, constitute the main dramatic art form of Thailand - S dance as well as T dance = Singular hence we need "Is" and not "are". Eliminate.
(C) The Sri-NuanSri-Nuan dance
and Teut-Teung dance
are an inherent part of Thai culture, and along with The Farmer's Dance, developed by the Ministry of agriculture,
constitute the main dramatic art form of Thailand - No S-V issues but the modifier developed by the ministry of agriculture is misplaced and long with others such as has been ommited.
(D) An inherent part of Thai culture,
the Sri-NuanSri-Nuan, Teut-Teung as well as other dances such as The Farmer's Dance, developed by the Ministry of agriculture, constitute the main Thai dramatic art form -
As well as cannot be used to connect 3 things. (E) The Sri-NuanSri-Nuan and Teut-Teung dances,
both inherent parts of Thai culture, and a dance developed by the Ministry of Agriculture named The Farmer's Dance, constitute, along with others, the main dramatic art form of Thailand - The meaning is correct and the structure is correct Both __ and ___
The sentence reads without modifiers as follows-
The Sri-NuanSri-Nuan and Teut-Teung dances, and the Farmer's Dance, constitute, along with others, the main dramatic art form of Thailand.