Transition zone between two vegetational types is.
A. Ecotone
B. Ecotype
C. Ecoline
D. Ecosystem

Hint:It may exist along a broad belt or in a small pocket, such as forest clearing, where two local communities blend together. The influence of the two bordering communities on each other is known as the edge effect.

Complete answer:
Transition zone between two vegetational types is ecotone which can be defined as an abrupt change in vegetation or two adjacent, different and homogeneous community types producing a narrow ecological zone.
It can be local or regional depending upon a zone between a field and forest local or the transition between forests and grassland ecosystem.
Ecotone is a transitional zone between two ecosystems such transition can be seen while moving from land to water. In this zone species of both ecosystems can be found.
Ecotype is a species that is adapted to live in a particular habitat. This species is genetically modified to survive in the particular habitat.
Ecoline consists of ecotypes where the species gradually changes as we move from one ecosystem to another. The changes are both phenotypic and genotypic.

Additional information: An ecotone is often associated with an ecoline (a physical transmission zone between two systems). The ecotone and ecoline concepts are sometimes confused.

Hence, the correct answer is option A.

Note:Basically ecotone is a transition area between two biomass which are dynamic sometimes with strong fluctuation. An ecotone can be formed naturally through abiotic factors such as changes in soil composition but can also be created through the result of human interaction. Clearing of forest areas or irrigation are examples of this.