Fill in the blank with an appropriate article.
Rustom was {Fill-Regular} young Parsee.

Papers are words that designate whether a given noun is distinct or foggy. There are three papers- a, an and the. 
Let us look at the uses of the three papers. 
‘ A ’ is used when we're speaking about just one noun. Note that these nouns must begin with consonant letters like B, C, D, F, G and so on. The composition a can not be used with a noun that begins with a vowel. This would make it a grammatical error. Fore.g. A mountain. 
‘ An ’ is also used when we're speaking about just one noun. still, unlike the composition a, the composition an is used before nouns that begin with the five vowels, videlicet, A, E, I, O andU. Using the composition an along with a consonant would render it grammatically incorrect. Fore.g. An egg. 
‘ The ’ is used when speaking about further than one noun.E.g. The pens. The is also used when we're speaking about commodity in particular or when commodity has formerly been spoken about ahead. Fore.g. The sun, The United States of America,etc. 
In the below question, we've to use an composition that stands for a singular noun. likewise, as that noun is anteceded by an adjective beginning with a consonant, we must use a consonant compatible composition. This makes option ‘ b ’ a, the correct answer. 
therefore, option ‘ b ’ is the correct answer.