Select all of the following that are true about autosomal recessive inheritance of a human disorder.
Multiple select question.

a) The disorder typically appears in every generation, and only one copy of the disease-causing allele in necessary to cause the disorder.
b) Both parents of an affected individual carry at least one copy of the disease-causing allele.
c) One or both parents of an affected individual must have the disorder.
d) The disorder is seen more often in males.
e) Heterozygous individuals are called carriers.