**Core Concept**
The question is testing the concept of the duration of action of non-depolarizing muscle relaxants and their spontaneous recovery profile. Non-depolarizing muscle relaxants have varying durations of action, and some have a high tendency for spontaneous recovery.

**Why the Correct Answer is Right**
The patient most likely received Rocuronium, a non-depolarizing muscle relaxant with a relatively short duration of action (about 30-45 minutes). Rocuronium has a high propensity for spontaneous recovery, making it likely for the patient to recover from its effects without any reversal agent. This is due to its rapid hydrolysis by plasma cholinesterase enzymes, which breaks down the drug into its inactive metabolites.

**Why Each Wrong Option is Incorrect**
* **Option A:** Vecuronium has a similar duration of action to Rocuronium but does not have as high a propensity for spontaneous recovery as Rocuronium.
* **Option B:** Atracurium has a duration of action similar to that of Vecuronium and does not have a high tendency for spontaneous recovery.
* **Option C:** Pancuronium has a longer duration of action compared to Rocuronium and does not have a high propensity for spontaneous recovery.

**Clinical Pearl / High-Yield Fact**
It is essential to remember that the duration of action of non-depolarizing muscle relaxants can vary significantly among individuals, and some patients may experience spontaneous recovery from the effects of these drugs.

**Correct Answer:** D.