Answer is E

Is it B?

Blooming is the difference provided as information considered for identifying if the hydrangeas is panicled or not. Hence if option C is not true, we can never conclude that hydrangeas is not panicled.
Hence I go with Option C.

The conclusion need not assume or depend on the common features. Hence not A.
If a hydrangeas is panicled it is not bigleaf need not be true to be correct otherwise as the conclusion is. Hence not B.
All hydrangeas blooming in late summer is of no use. It is not connected with conclusion and instead talks further about the first premise presented. Hence not D.
As to when hydrangeas used by florists bloom is of no use. Hence not E either.

Imo E

Late summer->p
Florists->BL
Florists->not p

Negate E:
of flowers used by florist some grew in late summer then florists-> p or BL

sk8ternite wrote:If the hydrangea blooms in late summer it is a panicled hydrangea. If it is grown for florists, it is a bigleaf hydrangea. This hydrangea is grown for florists and is therefore not panicled.

The argument above relies on which of the following to reach its conclusion?

a. the panicled hydrangea has no features in common with the bigleaf hydrangea
b. if a hydrangea is panicled, it is not bigleaf
c. no bigleaf hydrangea blooms in the late summer
d. all panicled hydrangea blooms in the late summer
e. of the hydrangeas used by florists, none blooms in the late summer

OA is B

B is the most suitable option in this case.