The correct answer is D. Fallen leaves and blossoms spread out from its borders.
Step-by-step explanation:
The description "The garden was untended and overgrown with weeds and dying plants" suggest the garden had been neglected and overtime some plants such as weeds had grown with no control while others had begun to die, probably due to the lack of water, fertilizers, and proper care. In this context, the sentence that continues the description also needs to refer to the messy and neglected state of the garden and therefore, the best option is "Fallen leaves and blossoms spread out from its borders" because this continues with the same idea of the first description that is an unkempt garden.