In which phyla of animals is an open circulatory system found?

How many of the following characteristics are common to both Amphibians and Reptiles?
$a$ - Type of fertilization
$b$ - Cold-blooded (Poikilothermic)
$c$ - Development
$d$ - Oviparous
$e$ - Coelomate
$f$ - Bilateral symmetry

The difference between male and female $Anopheles$ occurs in:

Coelom is absent in

Which one of the following is not a deuterostome?

Which of the following fundamental features is common to $Balanoglossus$,$Anopheles$,and $Laccifer$ without any exception?