The image where a chemical reaction has not taken place is the one where seeds grew. Option 4 is correct.
The growth of seeds is not a chemical process. It is referred to as germination in biology. Given the proper circumstances (moisture, warmth, and oxygen), seeds take up water and nutrients from the soil and begin to grow. Rather than a chemical reaction, its growth is caused by the seed's internal biological processes activating.
So, The picture of the seeds growing is the one in which there hasn't been any chemical reaction. The other examples include chemical processes, such boiling water, browning marshmallows, and cooking eggs.