Final answer:
The sentence in question does not clarify whether Millennial Media has one or more marketing consultants; it only states Dan Harding's achievement in establishing a social media presence.
Step-by-step explanation:
The sentence "Millennial Media's marketing consultant, Dan Harding, achieved the company's first-quarter marketing goal of establishing an active social media presence" does not definitively suggest whether Millennial Media has more than one marketing consultant or only one.
The presence of the definite article 'the' before 'marketing consultant' could imply that Dan Harding is the sole marketing consultant at the company. However, the sentence's focus is on what Dan Harding achieved, not on the number of marketing consultants at Millennial Media.
The sentence suggests that there is one marketing consultant named Dan Harding at Millennial Media, and he successfully achieved the company's first-quarter marketing goal of establishing an active social media presence.
Therefore, we cannot determine the exact number of marketing consultants at the company based on this sentence alone.