Alchemy aimed at finding………which was considered mythical and magical substance.
Philosopher's Stone
The explanation for correct option A:
The philosopher's stone was supposed to possess many valuable attributes such as the power to heal, prolong life, and change base metals into precious metals — such as gold.
The explanation for incorrect option B: Alchemy aimed to transform the base metals into gold by mythical and magical means.
The explanation for incorrect option C: Alchemy aimed to transform the base metals into gold by mythical and magical means.
The explanation for incorrect option-D: Zinc doesn't consider a precious or Nobel metal.
Concluding Statement: For the above reasons, Option A is the correct answer.