**Solution:**

To analyze the given inequality, we can cross-multiply to get:

(a/b) > (c/d)
ad > bc

Now let's consider each statement one by one:

**Statement 1: a/b - c/d > 0**

To determine whether this statement is true, we need to substitute the values from the given inequality.

Here, we have ad > bc.

If we subtract c/d from a/b, we get:

(a/b - c/d) = (ad - bc) / bd

Since ad > bc, we can conclude that (ad - bc) is greater than zero. Moreover, bd is always positive as b and d are both positive quantities.

Thus, we have (ad - bc)/bd > 0, which means that a/b - c/d > 0. Therefore, statement 1 is true.

**Statement 2: ad is less than bc**

From the given inequality ad > bc, we can conclude that ad is not necessarily less than bc. In fact, ad can be greater than or equal to bc. Hence, statement 2 is not necessarily true.

**Statement 3: ad is greater than bc**

The given inequality ad > bc directly implies that ad is greater than bc. Therefore, statement 3 is true.

**Conclusion:**

From the analysis above, we can conclude that statement 1 (a/b - c/d > 0) and statement 3 (ad is greater than bc) must be true. On the other hand, statement 2 (ad is less than bc) is not necessarily true.

Therefore, the correct answer is **Option 4: All of the above**.