Test analysis: the price of goods is determined by value and influenced by the relationship between supply and demand. The chart of this topic reflects the overall upward trend of agricultural product prices in China. The measure of item 1 "integration of production, supply and marketing of agricultural products" is conducive to reducing the cost and stabilizing the price of agricultural products, which is in line with the meaning of the question and can be chosen; The fourth measure of "promoting agricultural technological innovation and improving labor productivity" is conducive to increasing the supply and stabilizing the prices of agricultural products, which is in line with the meaning of the question and can be chosen; Neither of the two measures can stabilize the price of agricultural products, so they are irrelevant and cannot be chosen. So, the answer is D.