Answer:
The correct answer is -Sponges lack true tissue but have morevariation in cell type than animas in oter phylum.
Explanation:
Sponges are belong under phylum porifera which have diverse form encrusting sheets to volcano shaped mounds.
The tubes that contain in their body are differ in size from millimeter upto one meter.
The poriferans contain canal system and with help of this, they pump water which enters through a specialed pores called ostia that flows through canal called spongocoel and finally the water exits from their body through oscula.
The sponges show complex organization as their body contain single tube with 2 cell layer thick.
Ascon,leucon,sycons are the level of complexity.