Step 1: Separate the two related terms.
Public health texts describe both a maternal mortality rate and a maternal mortality ratio, and questions like this test the exact wording each textbook uses.
Step 2: Recall the definition used in Indian preventive and social medicine texts.
Standard Indian community medicine textbooks such as Park's define the Maternal Mortality Rate as the number of maternal deaths in a year, divided by the total number of live births in that year, expressed per 1000 live births. This is the definition this question is built on.
Step 3: Note the international convention.
The World Health Organization instead reports a Maternal Mortality Ratio, expressed per 100,000 live births, which is the figure most often quoted in global health statistics today. Both measures use the same idea, maternal deaths compared to live births, but they differ in scale and in the exact name used.
Step 4: Match to the given options.
Since the question is set from the Indian textbook style definition of the rate, the correct denominator here is per 1000 live births, matching option (A).
Step 5: Final answer.
So, per this definition, maternal mortality is deaths per 1000 live births.
\[ \boxed{\text{1000 live births}} \]