In Ascomycetes, which of the following structures produces asexual spores?

The correct answer is Conidiophore

Explanation:

Characteristics of Ascomycetes:

• Known as sac fungi.
• Asexual reproduction is by conidia.
• Conidia produced exogenously on the special mycelium called conidiophores.
• Produce sexual spores called ascospores in a sac-like structure called an ascus.
• Ascospores are produced endogenously in sac like asci (singular ascus). 
• Mycelium is branched and septate.
• Examples: Aspergillus, Claviceps, Neurospora,Penicillium

Sporangium: The sporangium is a structure that produces spores in other groups of fungi, particularly Zygomycetes, but it is not the structure responsible for asexual spore production in Ascomycetes.