A friend sent you this.

Choose one answer

1. AIncreased cerebrospinal fluid pressure causing a reflex pupillary dilation response
2. BSympathetic activation from blocked noradrenaline reuptake increasing radial dilator muscle tone
3. CCompetitive antagonism at muscarinic M3 receptors on the iris sphincter, as occurs with anticholinergic agents such as atropine
4. DBlockade of dopamine reuptake increasing synaptic dopamine at the nucleus accumbens
5. EDirect agonism at nicotinic acetylcholine receptors located in the iris sphincter muscle, which is not innervated by autonomic stimulant pathways