The correct answer is D. all.
Decision trees and neural networks (back propagation) are two of the most popular algorithms of machine learning. Decision trees are a type of supervised learning algorithm that can be used to classify or regress data. Neural networks are a type of machine learning algorithm that can be used to learn complex patterns from data. Back propagation is a technique used to train neural networks.
Probabilistic networks and nearest neighbor are also two popular algorithms of machine learning. Probabilistic networks are a type of graphical model that can be used to represent and learn the probability distribution of a set of variables. Nearest neighbor is a type of lazy learning algorithm that can be used to classify or regress data by finding the nearest neighbors of a given data point.
Support vector machines are a type of machine learning algorithm that can be used for classification or regression. Support vector machines work by finding a hyperplane that separates the data into two classes.
All of these algorithms are popular and have their own strengths and weaknesses. The best algorithm to use for a particular problem depends on the nature of the data and the desired outcome.