Reading Comprehension (RC) | Re: all of the cells in a particular plant start out

For Q3, agreed that Oligosachhariins perform specific function and plant root system is specific. But arent we inferring too far here because there is nothing mentioned in passage about oligosachharin and root system. Passage just mentions specific function:It can be any specific function but we dont know that from passage.
Please, can anyone throw light on this.