Among the following, the reaction that proceeds through an electrophilic substitution, is:

An alkene "A" on reaction with O₃ and Zn–H₂O gives propanone and ethanal in equimolar ratio. Addition of HCl to alkene "A" gives "B" as the major product. The structure of product "B" is:

• H₃C—CH₂—CH(CH₂Cl)—CH₃

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Provide an acceptable name for the alkene shown below:

• 5-ethyl-6-methyl-propyl decane

• 2-ethyl-6-methyl-2-propyldecane

• 2-ethyl-6-methyl-5-propyldecane

• 6-ethyl-2-methyl-5-propyldecane