The correct option is B Trimerous flower
Family Liliaceae is characterised by trimerous flowers. The flowers may be arranged (inflorescence) along the stem, developing from the base or as a single flower at the tip of the stem or as a cluster of flowers. They contain both male (androecium) and female (gynoecium) characteristics and are symmetric radially, but sometimes as a mirror image. Most flowers are large and colourful.
So, the correct answer is 'Trimerous flower'