According to te question

Let the first even number be 'x'

And the consecutive even numbers be x,x+2,x+4,x+6

Sum of four consecutive numbers = 284

⇒ x+(x+2)+(x+4)+(x+6)=284

⇒ 4x+12=284

⇒ 4x=284-12

⇒ 4x=272   [divide both sides by '4']

We get,

⇒ x=68

So, '68' is the smallest number followed by 70,72,74.

Hence, Option C is correct.