Final answer:
To form the word 'bigger' from the root 'big' plus the suffix '-er', we double the final consonant before adding the suffix. This follows the spelling rule for doubling the final consonant when a single vowel is followed by a single consonant.
Step-by-step explanation:
The question asks us to add the suffix -er to the root word big following the correct spelling rules. When adding -er to a word ending in a single vowel followed by a single consonant, we double the final consonant before adding the suffix. Therefore, the correct answer is bigger (A. bigger).
In the additional exercise provided, we apply various spelling rules when combining prefixes, bases, and suffixes to form new words. For instance, we consider doubling of consonants, deleting final e, and changing a y to i when applicable. These rules are crucial to maintain the correct pronunciation and meaning of the newly formed words.