The correct answer is option-1 Positive. According to simple Keynesian theory, the slope of the aggregate consumption curve against income is positive. This means that as income increases, consumption also increases. The reasoning behind this is that as individuals and households earn more income, they have more money available to spend on goods and services. Therefore, they are likely to increase their consumption. This positive relationship between income and consumption is a fundamental concept in Keynesian economics.

It`s important to note that this relationship assumes that there are no other factors influencing consumption, such as changes in interest rates or consumer sentiment. Additionally, the slope of the aggregate consumption curve may vary depending on specific economic conditions and the income range being analyzed. However, in simple Keynesian theory, the general relationship is one of a positive slope.